Wet processing installation

ABSTRACT

An installation for wet processing, such as electroplating, in which a plurality of wet processing tanks are arranged in a line and a single rinsing zone is arranged at one location in the line. A trolley is movable over the tanks and rinsing zone and includes lifting mechanism carried by the trolley to lift and lower a workpiece out of and into a tank beneath the trolley to and from a location above the level of the tops of the tanks. A drip tray is carried by the trolley for movement therewith and is movable between a first position permitting the lifting and lowering of a workpiece, and a second position beneath the lifted workpiece to catch any drips therefrom as the trolley moves over the various tanks.

United States Patent Morley [451 Oct. 24, 1972 [54] WET PROCESSING INSTALLATION 72] Inventor: Cyril William James Morley, 59 r F 'i Bleuge Yockley Close Cambefley, England Attomey-Flett, Gipple and Jacobson [22] Filed: June 15, I971 [57 7 ABSTRACT [21] P 153,276 An installation for wet processing, such as electroplating, in which a plurality of wet processing tanks are ar- [30] Foreign Application p i Data ranged in a line and a single rinsing zone is arranged at one location in the line. A trolley is movable over the June 1970 Great tanks and rinsing zone and includes lifting mechanism carried by the trolley to lift and lower a workpiece out :LtSiI. "134/76 i a k b th the trolley to and from a lod 117 135 cation above the level of the tops of the tanks. A drip 1 re tray is carried by the trolley for movement therewith and is movable between a first position permitting the [56] References cued lifting and lowering of a workpiece, and a second posi- UNITED STATES TEN tion beneath the lifted workpiece to catch any drips 3 039 432 6/1962 Le B Hr t al 134/1 17 X therefrom as the trolley moves over the various tanks.

9 Cu I let 6 3,074,417 1/1963 Lisowski et al 1 34/76 10 Claims, 6 Drawing Figures F T. 4 J I (j 24 I i g f /8 8/9 a: .i-JL 25 /7 I l 5; )5] I I EL. 1 1L q- L$-' 25 2/ 16 i 1 T 1- jf'.f f; r 7

PATENTED 24 I97? 3. 699,983

lnvenlor Cyril VB I Morley M tlorneys PATENTEDncm m2 9.699.999

SHEET 3 [1F 4 WET PROCESSING INSTALLATION The present invention relates'to wet processing such as electroplating, electrophoretic processing, anoding and pickling. v

The conventional method of electroplating consists in providing a number of electroplating baths in -a row of tanks. Intermediate the various electroplating baths are further tanks for rinsing the chemical from an article to be plated before it moves to the next bath. It is quite common to have an arrangement in which there are, for example, eight electroplating baths arranged in eight tanks and for there to be as many as twenty further tanks containing water, either in a static state or with flow of water therethrough to effect the washing. Thus, there is always one washing tank between each adjacent pair of electroplating tanks and veryoften it is necessary to have two or three wash tanks to remove the chemical to the required degree. Naturally, the electroplating installation is necessarily very large if such a large number of tanks is required.

In order to move the materials to be plated from one tank to another, it is common practice to provide trolleys which run on rails above the .row of tanks; these trolleys have incorporated therewith raising and lowering means to remove and insert the articles to be electroplated on carriers in the various baths and tanks. In one known arrangement each of the trolleys is programmed to operate automatically to move the material to be plated into and out of the bath in the correct sequence and so that material has the correct duration in each tank. It will be appreciated therefore that a large number of trolleys have tobe provided and this is costly both as a capital outlay and in maintenance.

Similar considerations apply with regard to other forms of wet processing, for example as mentioned above.

It is now proposed, according to the invention, to provide a wet processing installation comprising a plurality of wet processing tanks arranged in a line and a single rinsing zone arranged at one location in the line, a trolley movable over the tanks and rinsing zone, lifting means carried by the trolley to lift and lower a workpiece out of and into a tank beneath the trolley, to and from a location above the level of the tops of the tanks, and a drip tray, carried by the trolley for movement therewith, and movable from a first position permitting the lifting or lowering of a workpiece to a second position beneath a lifted workpiece. Using such an installation, the number of trolleys can be reduced, preferably to one, and this trolley can be in operation substantially the whole of the time so that it has no down-time.

The rinsing zone may be a single tank or number of tanks, which, for convenience, may in an electroplating process be arranged at the center or one end of the line of electroplating bath tanks, and the tank or tanks may contain static water or running water. Where more than one rinsing tank is provided, it is possible to pro vide a transfer device movable along the line of rinsing tanks to move workpieces from one rinsing tank to another. Preferably, the transfer device comprises a track beneath the rinsing tanks and a second trolley movable along the track, the second trolley being programmed so as not to interfere with the travel of the trolley movable over the wet processing tanks.

' In an altemativeconstruction the rinsing zone may include spray jets which serve to wash the articles by a spray shower arrangement rather than by simple immersion in a tank of water.

The installation of the invention includes a drip tray arrangement, which prevents he chemicals which drip from the articles to be plated falling into a subsequent tank and contaminating the bath therein as the trolley moves with the load to the rinsing zone. The drip tray may, for example, be in the form of a pair of sliding or hinged doors or may be in the form of a roller shutter which can close oh the bottomof the trolley. The trolley could in fact be an enclosed housing with an openable bottom and that the trolley itself be provided with spraying devices.

According to a preferred construction, the drip tray is movable linearly in a direction parallel to the movement of the trolley 'over the tanks, and is in the form of an open topped tray having abottom wall and peripheral walls, a drainpipe connected to the tray at a location above the bottom wall and below the top of the peripheral wall to drain excess liquid from the tray, when the level thereof rises above the connection of the drainpipe to the tray. With this arrangement it is possible to maintain a mildly alkaline or acid solution in the tray so that no violent reactions result from the mixing of the drips from different tanks. Advantageously, the drainpipe is provided, at the end remote from the connection to the tray, with a portion which is pivotal from an upwardly directed position, with its free end above the connection to a downwardly directed position, permitting liquid in the pipe to drain to waste, means being provided to pivot the end portion to the downwardly directed position, when the trolley reaches a particular-position with respect to the tanks.

The drain pipe maybe connected to the tray by means of an annular weir extending upwardly from the bottom wall.

As has been indicated the present invention enables the total size of the electroplating plant to be reduced considerably, thus, instead of having .a total of 28 or 30 tanks, as in the previously discussed arrangement, it will be possible to have as few as 10 tanks, i.e., eight electroplating bath tanks and two rinse zone tanks. This, of course, reduces the capital cost and the amount of floor space required. A further advantage is that the whole installation can be enclosed or surmounted by a hood, and the vapors given ofi can be extracted by conventional axial flow fans arranged along the length of the hood. In a prior construction the hood had to be of such very large dimensions that the negative pressure provided by the fans was insufficient, and comparatively costly centrifugal fans had to be provided.

In order that the invention may more readily be understood, the following description is given, merely by way of example, reference being made to the accom- Referring first to FIG. 1, there is illustrated a line of wet processing tanks, such as electroplating tanks. In the drawings, there have been illustrated three tanks 10, 11 and 12, although in a practical construction there would be of the order of eight such tanks. Next to these tanks are 'three rinsing tanks 13, 14 and 15 together forming the single rinsing zone of the installation. The first tank 13 is the first rinse tank and receives water by overflow from a second rinse tank 14, which in turn receives water by overflow from a third and final rinse tank 15, which is fed with clean water through an inlet pipe 16.

A frame 17 is mounted above .the level of the tanks to and carries for movement thereover a first trolley 18, translational movement along the tracks of the frame 17 being effected by a drive motor 19. A lift motor 20 causes raising and lowering of racks 21 carrying the workpieces 22 to be wet processed. Slidably movable under the trolley 18 is a drip tray arrangement 23 which is movable from the full line position illustrated at the right in which it is to one side of the lifting arrangement 24, which is not illustrated in detail, and the phantom line position illustrated at the left in which it is underneath the lifting arrangement 24, this movement being effected by a motor 25. The trolley l8 is movable as a whole under the action of the motor 19 between the full line position illustrated at the right over the most right-hand tank 10 to the phantom line position over the most left-hand washing zone tank 15.

As illustrated in FIG. 2, the drip tray 23 comprises a lower or bottom wall 26 and a peripheral wall 27'extending therearound. Located in the lower or bottom wall 26 is an annular weir 28, the top of which is disposed at a level below the top of the peripheral wall 27. The annular weir is connected to a drainpipe 29 formed of a flexible resilient plastics or rubber material, this extending laterally to a position beyond the sides of the tanks. At its left hand end, as viewed in FIG. 2, the end portion of the hose is provided with an end fitting 30 which is mounted for rotation or pivotal movement in a tubular bearing 31. The end fitting is essentially a T-piece, the stem 32 of which is pivotal from the position illustrated in FIG. 2 and FIG. 3A to the position illustrated in FIG. 3B. Thus, it is pivotable between a generally upwardly extending position in which its open end is above the level of the annular weir 28 and a generally downwardly extending position as illustrated in FIG. 38, below the weir. Movement between the position of FIG. 3A and that of FIG. 3B is effected by an abutment 33 engaging a cam arm 34, while the return movement is caused either by a spring (not shown) or by the inherent resilience of the tube 29.

Referring now to FIGS. 4 and 5 there is illustrated a second trolley arrangement which may be mounted for movement under the tanks 13,14, 15, this second trolley being indicated by the reference numeral 35. The trolley is movable by means of a motor 36 along rails 37 and is provided with a pair of chains 38 rotatable by means of a motor 39 so as to raise and lower a lifting frame 40.

The frame 40 is movable from the position illustrated in full lines to the position illustrated in phantom and as it rises from the lower to the upper position, it lifts flight bars 41 for lifting racks 21 and workpieces 22 contained in either the rinsing tank 15 and the rinsing tank 14 or racks in the rinsing tank 14'and the rinsing tank 13. Location of the flight bars 41 is ensured by saddles 42 on the tanks. Similar saddles (not shown) are provided on the wet processing tanks 10 to 12.

In use of the above described apparatus, the trolley is movable on the rails of the frame 17 between the position illustrated in full lines and the position illustrated in phantom in FIG. 1. Supposing it is desired to lift a workpiece from the tank 10 and move it to a rinsing station, the trolley is moved by operation of the motor 19 to the position illustrated in full line in the Figure, and the drip tray is withdrawn to the position illustrated. Lifting arms (not shown) associated with the lifting arrangement 24 of the trolley 18 lift the racks 21,

with the workpieces 22 thereon, to a position above the level of the tanks and the motor 25 is operated to move the drip tray 23 under the racks. The drip tray has therein a dilute solution which is preferably alkaline and any wet processing material on the articles can drip off into the drip tray as the trolley moves to a location above the first rinse tank 13. The motor 25 is again operated to move the drip tray from beneath the workpieces which are then lowered into the rinsing tank 13. A further workpiece rack in the rinsing tank can now be lifted and the drip tray moved underneath again, whereupon the trolley moves back to move the second set of workpieces above the tank which they are destined to be placed in next. The trolley continues to move up and down the set of tanks under a controlled program lifting racks of workpieces as and when desired, and by this means it is possible for the trolley to have very little or no down-time. Naturally the drips from the workpieces will collect in the drip tray and the provision of an alkaline or other solution to suit the particular process ensures that no violent chemical reaction will take place as a result of two chemicals being dripped consecutively into the drip tray. The arrangement of the hose 29 andits associated end piece 30 is such that when the trolley gets to a particular location, for example, over the third rinsing tank 15, the end pieces tipped to the FIG. 3B position, the excess liquid formed above the weir can flow out through the pipe 29 to waste. The program of the trolley is so arranged that it arrives sufficiently often at the location where this takes place to ensure that no overflow occurs.

The provision of the second trolley 35 enables the workpieces in the rinsing tanks to be moved from one tank to the next. It will be appreciated that the water in the first rinsing tank 13 will be less clean than the water in the tank 14 which in turn will be less clean than the water in the tank 15. Thus, workpieces can be removed from a wet processing tank to the tank 13 and the trolley 35 can be used to transfer the workpieces leftwards to the other tanks to ensure greater cleaning of the workpieces, if this is necessary, between the placing the workpieces in two wet processing tanks. The programrning of the trolleys 18 and 35 is such that the trolley 35 only operates when the trolley 18 is away from the rinsing tanks 13, 14 and 15.

In some simple operations it will not be necessary to provide the second trolley and the trolley 18 can effect the whole of the transfer operations of the work cycle.

It will be appreciated that with the present invention only a relatively small number of rinsing tanks are necessary and that the trolley 18 is practically constantly working so that the down-time is reduced substantially to nil. This makes for far more efficient operation and since only one trolley is required for the transfer of the workpieces from the wet processing tank, the programming can be simplified as compared with conventional installations. Furthermore, the overall size of the apparatus or installation is greatly reduced so that the floor space'in the factory can be reduced and it is possible to provide a hood (not shown) which enables gases and vapors given off in the wet processing to be removed readily.

What I claim is:

1. A wet processing installation comprising, in combination:

a. A plurality of wet processing tanks arranged in a line;

b. a single rinsing zone arranged at one location in said line;

0. a trolley movable over the tanks and the rinsing zone;

d. lifting means carried by said trolley effective to lift and lower a workpiece out of and into the tank beneath the trolley, to and from a location above the level of the tops of the tanks;

e. a drip tray carried by the trolley for movement therewith; and

f. means for moving said drip tray from a first position permitting thelifting and lowering of a workpiece to a second position beneath a lifted workpiece.

2. An installation as claimed in claim 1, wherein said drip tray is movable linearly in a direction parallel to the movement of said trolley over said tanks.

3. An installation as claimed in claim 1, wherein said drip tray is open topped and comprises a bottom wall and peripheral walls, a drainpipe and means connecting said drainpipe to said tray at a location above said bottom wall and below the top of the peripheral wall, effective to drain excess liquid from the tray when the level thereof rises above said connecting means.

4. An installation as claimed in claim 3, and further comprising ends to said drainpipe, a portion of said drainpipe at the end remote from the connection to said tray, said portion being pivotal from an upwardly directed position, with its free end above the connection to a downwardly directed position permitting liquid in the pipe to drain to waste, and means to pivot the end portion to the downwardly directed position, when said trolley reaches a particular location with respect to said tanks.

5. An installation as claimed in claim 4, and further comprising an annular weir extending upwardly from the bottom wall, said annular, weir forming said connecting means.

6. An installation as claimed in claim 1, wherein said rinsing zone comprises a plurality of rinsing tanks.

7. An installation as claimed in claim 6, and further comprising a transfer device movable along the line of rinsing tanks effective to move workpieces from one rinsin tank to another.

installation as claimed in claim 7, wherein said transfer device comprises a track beneath the rinsing tanks and a second trolley movable along said track, said second trolley beingprogrammed' so as not to interfere with the travel of said trolley movable over the wet processing tanks.

9. An installation as claimed in claim 1, wherein said trolley is provided with an enclosed housing, into which the workpieces may be lifted, and further comprising spray devices within said housing effective 0 rinse the articles in the housing.

10. An installation as claimed in claim 1, wherein said rinsing zone includes spray jets for rinsing the workpieces. 

1. A wet processing installation comprising, in combination: a. A plurality of wet processing tanks arranged in a line; b. a single rinsing zone arranged at one location in said line; c. a trolley movable over the tanks and the rinsing zone; d. lifting means carried by said trolley effective to lift and lower a workpiece out of and into the tank beneath the tRolley, to and from a location above the level of the tops of the tanks; e. a drip tray carried by the trolley for movement therewith; and f. means for moving said drip tray from a first position permitting the lifting and lowering of a workpiece to a second position beneath a lifted workpiece.
 2. An installation as claimed in claim 1, wherein said drip tray is movable linearly in a direction parallel to the movement of said trolley over said tanks.
 3. An installation as claimed in claim 1, wherein said drip tray is open topped and comprises a bottom wall and peripheral walls, a drainpipe and means connecting said drainpipe to said tray at a location above said bottom wall and below the top of the peripheral wall, effective to drain excess liquid from the tray when the level thereof rises above said connecting means.
 4. An installation as claimed in claim 3, and further comprising ends to said drainpipe, a portion of said drainpipe at the end remote from the connection to said tray, said portion being pivotal from an upwardly directed position, with its free end above the connection to a downwardly directed position permitting liquid in the pipe to drain to waste, and means to pivot the end portion to the downwardly directed position, when said trolley reaches a particular location with respect to said tanks.
 5. An installation as claimed in claim 4, and further comprising an annular weir extending upwardly from the bottom wall, said annular weir forming said connecting means.
 6. An installation as claimed in claim 1, wherein said rinsing zone comprises a plurality of rinsing tanks.
 7. An installation as claimed in claim 6, and further comprising a transfer device movable along the line of rinsing tanks effective to move workpieces from one rinsing tank to another.
 8. An installation as claimed in claim 7, wherein said transfer device comprises a track beneath the rinsing tanks and a second trolley movable along said track, said second trolley being programmed so as not to interfere with the travel of said trolley movable over the wet processing tanks.
 9. An installation as claimed in claim 1, wherein said trolley is provided with an enclosed housing, into which the workpieces may be lifted, and further comprising spray devices within said housing effective o rinse the articles in the housing.
 10. An installation as claimed in claim 1, wherein said rinsing zone includes spray jets for rinsing the workpieces. 